| 摘要 |
FIELD: electric engineering. ^ SUBSTANCE: method includes, in main mode, realizing load feeding 5 from main grid 3 through key 1. if main grid voltage exceeds preset limits, which is controlled by voltage sensor 6, comparator 8, and when backup grid is within preset limits, which is controlled by sensor 7, comparator 9, logical block switches load 5 to feeding through key 2 from backup grid 4. new section of method is, that in case of restoration of power from main grid 3 back switching can be performed only if load current, controlled by sensor 13 is lower then level of comparator activation. This excludes sudden current alternations possible during pause of switching under load. ^ EFFECT: higher reliability. ^ 1 dwg |
